Mr Kenny will address his parliamentary party - where he is expected to tell TDs when he plans to step down - something he had already promised, but rowed back on, following his St Patrick's Day trip to the US.

Mr Reilly also ruled out a live TV debate between the two contenders, Simon Coveney and Leo Varadkar - and confirmed reports that both men will be urged to conduct a "clean" campaign.

Long goodbye...Mr Kenny to finally address his future at parliamentary party tonight (Image: Brian Lawless/PA Wire)

He told RTE's Morning Ireland: "There is an ethics committee and obviously they are going to ensure that this election is carried out in an ethical fashion and that would be the Fine Gael way.

"Obviously nothing that would damage the party is clearly something that would be in there in terms of behaviour, in terms of tactics.

"But I believe that both candidates that we know of to date - and we don't know if there will be a further candidate or not - will abide by that. They're both honourable men."

On the prospect of a TV debate ahead of the election of Mr Kenny's successor, Mr Reilly said he did not think "that finds favour with the executive" as party chiefs feel the election is an internal matter.

As he prepares to step down as deputy leader, he said he had been "very privileged" to serve a party he claimed had "brought the country back from the brink".

On Mr Kenny's legacy, he added: "There's a huge challenge to fill the boots of Enda Kenny, who's done an astonishing job and I think history will be extremely kind to him."